Improvement in balanced steam-valves



J.- A. STEPHENS. Balanced Steam-Valve.

No,208,344 Patented S'ept. 24,1878.

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UNITED STATES PATENT OEEIoE.

J OHNA. STEPHENS, OF LECOMTE, LOUISIANA.

IMPROVEMENT IN BALANCED STEAM-VALVES.

Specification forming part of Letters Patent No. 208,344, datedSeptember 24, 1878; application filed Y J nly 27, 1878.

To all whom it may concern:

Be it known that I, JOHN A. STEPHENS, of Lecomte, in the parish ofRapides and State of Louisiana, have invented a new and ImprovedBalanced Steam-Valve, of which the following is a specification:

My invention relates to valves for steamengines which are balanced bythe pressure of the steam, and is particularlyintended for thethrottle-valves, to render the working of them easier, so that theyrequire to operate them only power suficient to overcome the friction ofthe parts.

The said invention is also adapted to exhaust and governor valves.

My invention consists in a valve-stem supported in a valve-chamber by apiston-head at each end of the stem, and carrying a valve midway of itslength, which stem and valve are operated to open and close the valve bya screw-rod or other means.

In the drawing, Figure 1 is a vertical section of a valve andvalve-chamber embodying my invention. Fig. 2 is a sectional elevation ofone piston-head, and Fig. 3 is a plan of the valve-seat.

Similar letters of reference indicate correspondin g parts.

a is the valve'case, formed of two hollow cylinders united at theirflanged ends by bolts b, which bolts 1) also secure the intermediatering 0, forming the valve-seat. The steam comes from the boiler by thepipe (I, and passes to the engine by pipe 0.

f is the valve-stem, extending through the valve-case a from end to end,and carrying about midway of its length the valve h, which, when closed,rests upon the valve-seat c. The valve h consists of a metal disk aroundthe stem f, and having a socket to fit upon aball, i, on the stem f; andk is a ring withasimilar socket, secured by screw-bolts to h, so thatthe Valve 71- is held by the ball 2', but may turn thereon.

The outer ends of the valvechamber above the pipe (I and below the pipe6 are turned smooth, and the valve-stem f is provided at its ends withpiston-heads l and m, which fit into the said ends of the valve-chamber,so that the stem f is the piston of the heads land on. The heads 1 and mare packed, as at a,

rod (1, which takes under the edge of the ring 1'. This connectionpermits the rod q to turn independently of the stem f, but moves thestem endwise.

The screw-rod q is to be operated by a wheel or handle, 8, in any usualmanner, and it is evident that the rod q might be the valvestem of agovernor.

If the valve h be open, as shown in the drawing, the steam comes in at dand passes out at e. Thereby the pressure is equal upon the heads I andm in opposite directions, and the valve and stem are balanced. When thevalve h is closed upon its seat, the pressure will be in oppositedirections upon the head land valve h. In either position of the valvethe moving parts are balanced, and, whatever may be the weight of thesame, the power required to operate the valve needs only to besufficient to overcome friction.

The ends of the valve-case a may have caps t u bolted upon them, as seenin the drawing.

I do not limit myself to the details of construction set forth-that is,for instance, the connection of the valve and stem, the manner ofoperating the valve-stem, or the construction of the piston-heads. Thesemay be varied without departing from my invention.

Having thus described my invention, I claim as new and desire to secureby Letters Patent The combination of the valve-stem f, having an upperpiston-head, Z, a central valve, h, and a lower piston-head, m, with thevalve-casin g a, having an inlet-pipe, (1, above the valveseat '0, andan exit-pipe, 6, below the said valve-seat, substantially as and for thepurpose described.

JOHN ALEXANDE t STEPHENS. Witnesses:

J ULEs LAMERAUX, B. MAYER.

